1. Field of the Invention
This invention relates to plating of conductive materials on substrates which normally afford a relatively poor adhesion with such plating materials.
2. Background Art
A number of techniques have been developed for plating metals on different surfaces that normally provide poor bonding with the plating when conducted electrolytically. Illustratively, the plating may be carried out in a liquid phase, or the plating may be carried out by vapor deposition in a gas phase. Alternatively, the plating may be effected by sputtering.
Non-electrolytic plating is well known as a method for metallizing a surface of an electrically insulating material. For example, when the material to be plated is a ceramic such as an aluminum oxide sintered body, an aluminum nitride sintered body, or a silicon carbide sintered body, metallic palladium fine particles have been adhered to the surface thereof. A plating film is then formed thereon. The metallic palladium particles are formed on the surface by bringing an aqueous solution including palladium ions into contact with the ceramic surface and reducing it in situ.
A serious problem arises however because the palladium particles are not strongly adhered to the surface of the material to be plated and the plating therefore has poor adhesion to the substrate surface.
Where the ceramic is a sintered body, irregularities on the material surface cause adherence to be slightly improved as a result of the anchoring effect. However, when the material surface is smooth, such as with glass, the plating very often peels from the surface.
Also, when plating on organic polymers, the material surface may be as smooth as glass and adherence again has been found to be bad.